What makes a filter electrostatic?

An electronic air filter uses static electricity to give particles a positive charge when they enter the filter. This charge is released as air continues through the rear layers of the filter and ultimately causes the particle to be trapped. Electrostatic air filters are made of a filter medium that undergoes a process to charge them, creating attractive quality. Sometimes, multi-layer washable filters contain layers of materials intended to charge particles as they pass, making it easier for the attractive filter layer to work.

What particles do they trap? An electrostatic air filter is very efficient at capturing between 80 and 90 percent of dust, pollen, pet dander, bacteria, mold spores and indoor air smoke. This is a much higher capture rate than standard pleated fiberglass or cotton filters. If you suffer from a variety of airborne allergies, electrostatic air filters may be a reasonable way to reverse poor indoor air quality. An electrostatic filter is made of electrically charged media.

This type of air filtration system uses two plates. One has a positive charge and the other has a negative charge. The positively charged plate attracts negatively charged particles. Positively charged particles are attracted to the negatively charged plate.

All the electrically charged particles in the air in your home will be attracted to one of these plates. The particles stick to the plate until its surface is washed. Depending on your budget and your particular allergies, a HEPA filter or Molekule device may be a viable option for reducing allergen levels in the air. Typically, an electrostatically charged panel filter is installed directly in the HVAC system and is made of coarse-grained fibers.

Electrostatically charged filters are considered “flat filters”, unlike “pleated” filters, such as HEPA filters. Because electrostatic air filters are reusable, you won't have to order new filters every two months or wait in a long line at a store to buy what you need. However, the air purifier you choose should not be an electrostatic air filter device because of the levels of ozone it can generate. These still have a natural charge due to their construction material, and their load increases over time as the air that passes through the filter helps to build up some charge.

Electrostatic air filters ideally work as magnets for dust and any other particles floating in the air. This means that electrostatic precipitators cannot filter air from all particles with the same level of efficiency; this may depend on the size of the contaminant. Unlike washable filters, pleated filters don't have to be charged to have an electrostatic element. If you want to further improve your home's indoor air quality, electrostatic filters are compatible with UV-C air purifiers, whole-house fans, attic fans, and portable air purifiers.

Fibreglass filters may contain something like a static charge, but it's not enough to turn them into an effective filtering device. This is a reference to the filter medium and is independent of the category of electronic air filters that use an external power supply. Electrostatic filters come in one size only and fit almost all heating and air conditioning systems.